In certain consumable product applications, it is desirable to include two different flowable substances. In hair care products, such as shampoos and conditioners, the shampoo and conditioning substances are mixed in a predetermined ratio and packaged in a single cavity container. In other applications, containers having two cavities are used to keep the substances separate until they are dispensed. For example, certain toothpastes include both a gel substance and; a paste substance which are stored in separate cavities in the container and are co-dispensed.
Dispensing units having multiple chambers for holding different flowable substances are generally known. In one prior art dispenser, the flowable substances are stored in separate compressible chambers within a container, each chamber being provided with a dip tube. Secured to the top of the container is a metering and mixing output section. A metering mechanism includes a shaft on which a series of cams are mounted and a selector dial coupled to the shaft which function as a control element to rotate the cams. Each cam is arranged in the course of rotation to more or less pinch a respective dip tube, thereby determining the volume of constituent flow from each of the chambers into the output section.
Another prior art dispenser for holding, metering, mixing and dispensing a mixture of two substances comprises a container having two compartments for containing the two substances and a cylindrical neck at the top of the container having a first bore and a second bore, each communicating with a respective chamber in the container. A cylindrical mixing chamber communicating with the first and second bores is disposed over the cylindrical neck and includes a third bore on a top-end, thereof, for the egress of the two substances. The dispenser also includes a selector dial having a central opening concentrically disposed over the first bore for dispensing the substance from one of the compartments. A plurality of various diameter metering openings are disposed peripherally around the selector dial, concentrically disposed to pass over the second bore as the selector dial is rotated so that the substance from the other compartment is adjustable.
A third prior art dispenser comprises a cylindrical housing having a dispensing and a storage chamber enclosing a pair of containers for receiving flowable substances which are removably mounted on a mounting block. The block is provided with a pair of openings on an annular surface having a central projection about which a selector dial rotates. The projection includes a pair of passageways in fixed alignment with the openings so as to conduct a flowable substance therethrough. A regulating disk, including a plurality of different-sized openings, is movably disposed on the annular surface for revolving about the projection. When the regulating disk is moved in response to rotation of the selector, a selected disk opening is placed in registry between a block opening and a respective passageway, permitting the flowable substance within each container to pass into a blending relationship at the dispensing end.
The above-mentioned prior art dispensers provide metering by means of varying the openings of the chambers disposed within the container by means of a dial-valve or regulating disk to restrict the flow of material, and thereby alter the proportions of liquid by means of the restriction. These dispensers have erred in their conception that the substances are dispensed by exerting equal pressure on the compressible chambers within the compressible outer container. The results of applying pressure as described when holes are close in diameter does not result in altering the volume of the material extruded through the holes in any predictably variable way other than as a function of the amount of pressure exerted. Another disadvantage of the prior art dispensers is that they all employ a relatively complex structure involving relatively high manufacturing costs.
The present invention overcomes many of the disadvantages inherent in the above-described prior art dispensers by providing an apparatus for dispensing two flowable substances in a user selectable ratio in which the flow volume is varied by a selector member having a single opening. The dispensing apparatus includes a first container for receiving a first flowable substance, with the first container having a uniform cross-section and having a first, generally open dispensing end, and a second end which initially includes a piston. The piston is movable only toward the dispensing end of the first container as the flowable substance flows out of the dispensing end. The apparatus also includes a second container for receiving a second flowable substance, with the second container having a uniform cross-section including a first, generally open dispensing end, and a second end which initially includes a piston. The piston is movable only toward the dispensing end of the second container as the second flowable substance flows out of the dispensing end. The dispensing ends of the first and second containers are removably received in the inlet end of a manifold member. The manifold member has an inlet end and an outlet end, and a pair of inlet openings. The manifold member is internally divided into two chambers. The first chamber is in fluid communication with the dispensing end of the first container, for receiving the first flowable substance, and the second chamber is in fluid communication with the dispensing end of the second container, for receiving the second flowable substance. The outlet end of the manifold member has a pair of outlet openings corresponding to the inlet openings so that the first and second flowable substances from the first and second containers flow into the respective inlet opening, through the respective chambers and out of the respective outlet openings of the manifold member. The dispensing apparatus also includes a pump member having an inlet end, in fluid communication with the first and second manifold chambers, and an outlet end. The pump member is movable with respect to the manifold member. A selector member is in fluid communication with outlet end of the manifold member. The selector member has a single opening of a predetermined size extending therethrough. The selector member is selectably rotatable with respect to the outlet end of the manifold member from a first position, in which the selector member opening is in fluid communication with the outlet of the first chamber of the manifold member, with the outlet of the second chamber of the manifold member being blocked by the selector member, through a plurality of intermediate positions, in which the opening of the selector member is in fluid communication with portions of the outlets of both of the manifold member chambers, with the remaining portions of the outlets of both of the manifold member chamber being blocked by the selector member, to a second position, in which the opening of the selector member is in fluid communication with the outlet of the second chamber of the manifold member and the outlet of the first chamber of the manifold member is blocked by the selector member. A single dispenser outlet opening is provided in communication with the selector member. Upon movement of the pump member by a user, a predetermined measure of flowable substance is dispensed from the apparatus with the ratio of the flowable substance being selectively variable by the user from 100% of the first flowable substance and 0% of the second flowable substance, when the selector member is in the first position, to 0% of the first flowable substance and 100% of the second flowable substance, when the selector member is in the second position, through a plurality of intermediate positions providing varying ratios of the first and second flowable substances.